Mitsui was originally the shipping department of the trading
company Mitsui Bussan Kaisha. Mitsui Bussan was established in 1876 and
obtained exclusive rights to export and market the coal mined at the
state-run Miike mines. It chartered ships and transported coal on its
own account.
In 1878 they bought a steamship, and in 1888 they bought the mines. Mitsui Bussan
became an industrial carrier and the shipping section was established in 1898.
The section expanded to become the Shipping Department and moved to Kobe in 1904.
The company then owned 9 ships aggregating 36,752 DWT, and on the eve of World
War I the fleet totalled 15 ships with 74,635 DWT, increasing to 30 ships totaling
127,141 DWT in 1919.

In 1914 a tramping service was started carrying the company's
own cargo and that of other companies. In 1917 a shipyard was constructed
and a shipbuilding department
was set up and in 1920 it opened a semi-liner service from Dalian via Kobe
to Seattle, whereby a liner service operated on outbound voyages but
on the return
voyage, owing to insufficient cargo at Seattle, ships had to stop and collect
cargo at other ports.

In 1928 Mitsui opened a Bangkok route, in 1931 a Philippines route,
in 1932 a Dalien to New York route, and in 1935 a Persian Gulf route.
From 1933 the Shipping Department became known as Mitsui Line. In 1937
it owned 35 ships aggregating 227,044 DWT. The shipbuilding department
was separated off as the Mitsui Tama Shipyard in 1937, and in 1942 the
former Shipping Department too became a separate company, Mitsui Steamship
Co., Ltd.

In 1943 several smaller shipping companies were merged with Mitsui Steamship
Co. During World War II, and after the war, all Mitsui ships were
under the control of the government. When Japan lost the war in 1945,
only 17 of Mitsui’s vessels were
left, increasing to 22 vessels totaling 77,459 DWT when Mitsui re-acquired
operations that had previously been chartered out to the Civilian Merchant
Marine Committee (CMMC). Mitsui then began a vigorous expansion of its
fleet and routes to re-establish its pre-war network.

Mitsui constructed 38 vessels between 1950 and its merger with OSK in
1964, and its operating tonnage was the largest in Japan. One of its
ships, Kinkasan Maru, was the first bridge-controlled ship in the world.
Mitsui planned to rationalize its crews and at the same time improve
the working conditions of engineers. It cooperated with Mitsui Shipbuilding & Engineering
Co., a direct successor of Mitsui Tama Shipyard, and designed innovatory
bridge-controlled ships. The Kinkasan Maru was delivered in 1961 and
Mitsui placed it, along with another bridge-controlled ship, on the New
York route, which was re-opened in 1951. Besides the New York route,
Mitsui operated westbound and eastbound routes around the world, a Central
and South America route, a West Africa route, and a Great Lakes route.
In 1964 Mitsui owned 45 vessels aggregating 737,098 DWT. However, Mitsui's
performance was disappointing from 1950 until the O.S.K. merger in 1964.
Another shipping company Ryoto Kisen K.K. was managed by Mitsui Bussan
Kaisha with ships names also ending …san Maru.

Many thanks to Henk Jungerius and Ted Finch for his assistance in
collecting this data. The following list was extracted from various
sources. This is not an
all inclusive list but should only be used as a guide. If you would like
to know more about a vessel, visit the Ship
Descriptions (onsite) or Immigrant
Shipweb site.

built by Mitsui Bussan
Kaisha, Tama | 1938 renamed Aobasan Maru (according to Jordan), 30
October 1944 bombed and sunk by American bombers with the loss of
2 lives.

8,812

Ayatosan Maru

1939

built by Tama Shipbuilding Co., Tama | 21 July 1942
bombed and sunk by American bombers NE Coast of New Guinea with the
loss of 3 lives.

9,788

Azuchisan Maru (1)

1944

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | Standard ship type 2A, 02 October 1944 torpedoed and
sunk by submarine.

6,888

Azuchisan Maru (2)

1953

built by Nihonkai Dock, Toyama | Built for Kusakabe
Kisen K.K., Tokyo, 1964 Mitsui merged with O.S.K. to
become Mitsui OSK Lines, 1973 sold to C.T. Chu renamed Good Fortune,
1973 sold to First International Shipping renamed Sara Sun, 21 December
1973 sank in tow.

built by Harima Dockyard, Harima | ex- Meiji Maru
built for Sakai Shoten, 1933 sold to Shimatani Kisen K.K. renamed
Kosei Maru, taken over with Shimatani Kisen K.K. fleet, 27 January
1944 torpedoed and sunk by American submarine USS Thresher.

2,681

Kotohirasan Maru

1945

built by Mitsui Akitsu Shipyard | Standard ship type
2D-1, 05 August 1945 torpedoed and sunk by American submarine USS
Pogy near Funakawa.

2,220

Koyasan Maru

1927

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | 10 February 1935 wrecked Kaminoshima, near Daiosaki.

1,998

Kumanosan Maru

1943

built by Nagoya Drydock, Nagoya | 23 June 1944 torpedoed
and sunk by American submarine USS Grouper with the loss of 1 life.

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | 1943 converted into a landing craft carrier for the
Army, 17 November 1944 torpedoed and sunk by American submarine USS
Picuda with the loss of 3,432 lives.

9,433

Mayasan Maru (3)

1958

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | 1964 Mitsui merged with O.S.K. to
become Mitsui OSK Lines, 1979 scrapped at Kaohsiung

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | ex- Nihonkai Maru, 1943 taken over with fleet of Shimatani
Kisen K.K., 17 June 1944 torpedoed and sunk by American submarine
USS Flounder.

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | Standard ship type 2A-20 dry cargo, converted into
a tanker, 17 November 1944 torpedoed and sunk by American submarine
USS Peto with the loss of 142 lives

6,925

Oshima Maru

1934

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | 1952 sold to Sugaya Kisen, 1967 scrapped at Nose.

970

Otorisan Maru

1943

built by Harima Dockyard, Harima | Standard tanker
type TM, 26 July 1944 torpedoed and sunk by American submarine USS
Flasher and USS Crevalle with the loss of 46 lives.

5,280

Otowasan Maru (1)

1936

built by Mitsui Bussan Kaisha, Tama | Tanker, 22 December
1944 torpedoed and sunk by American submarine USS Flasher with the
loss of 62 lives.

built by Mitsui Engineering and Shipbuilding Co.,
Tamano Works | Standard ship type 1B-1,18 October 1944 1944 torpedoed
and sunk with troops by American submarine USS Raton with the loss
of 1426 lives.

built by Mitsubishi Zosen Kaisha, Nagasaki | ex- Tenkai
Maru built for Suzuki Shoten, 1927 sold to Meiji Kaiun, 1933 sold
to Shimatani Kisen K.K., 1943 taken over with fleet of Shimatani
Kisen K.K., 05 September 1943 sunk by submarine.

built by Ono Ironwork Shipyard., Osaka | ex- Tokiwa
Maru built for Hamaguchi Kisen, 1924 sold to to Shimatani Kisen K.K.,
1943 taken over with fleet of Shimatani Kisen K.K., 09 June 1945
torpedoed and sunk by American submarine USS Seadog.

914

Tokiwasan Maru

1938

built by Mitsui Bussan Kaisha, Tama | 09 September
1944 torpedoed and sunk by American submarine USS Bang with the loss
of 9 lives.

built by Osaka Iron Works, Innoshima | ex- Tsukushi
Maru built for Kaijima Shogyo, 1943 purchased from Hokkaido Kisen,
23 August 1943 torpedoed and sunk by American submarine USS Tang.

1,858

Tsukushi Maru No. 2

1926

built by Uraga Dock Co. Ltd, Uraga | ex- Tsukushi
Maru No. 2 built for Kaijima Shogyo, 1943 purchased from Hokkaido
Kisen, 11 July 1944 torpedoed and sunk by American submarine USS
Sealion with the loss of 38 lives.

2,423

Tsukushi Maru No. 3

1927

built by Harima Dockyard, Harima | ex- Tsukushi Maru
No. 3 built for Kaijima Shogyo, 1943 purchased from Hokkaido Kisen,
18 March 1945 torpedoed and sunk by American submarine USS Trigger
NW of Naze with the loss of many lives.

built by Charles Connell & Co., Glasgow | ex- Glenlyon
built for James Gardiner & Co., 1917 to Furness, Withy & Co., ex-
Indian Prince 1919 for the Rio Cape Line, management was transferred
to Prince Line Ltd in 1922,
1936 sold to A. I. Cosmas, Panama renamed Andreas, 1941 seized by
the Japanese in the Dutch East Indies, renamed Wakatsu Maru and placed
under the management of Shimatani, 1943 taken over with fleet, 16
December 1942 was sunk off East Timor by Dutch aircraft from Darwin.